Non-prismatic heat exchanger construction

ABSTRACT

A non-prismatic heat exchanger with a modular construction for use with an engine which utilizes a coolant fluid. The heat exchanger includes a pair of unitary, non-prismatic-shaped headers spaced from one another and connected by a plurality of unitary, extruded heat exchanger modules. The headers and modules enclose a rotary fan within the interior of the heat exchanger. The fan is mechanically driven by the engine to draw cooling air into the interior of the heat exchanger and to concurrently force the cooling air outwardly between the heat exchanger modules to thermally contact and remove heat from the heated coolant fluid flowing through the modules.

FIELD OF THE INVENTION

[0001] The present invention relates to heat exchangers for use in automobiles, and more specifically to a heat exchanger including a pair of non-prismatic headers connected by one or more unitary, extruded heat exchanger modules that enclose a rotatable fan.

BACKGROUND OF THE INVENTION

[0002] In order to reduce the temperature of a coolant flowing out of an internal combustion engine, such as an automobile engine, a heat exchanger is utilized. The heat exchanger enables the coolant to flow through tubes within the heat exchanger that are in thermal contact with a cooling fluid. The cooling fluid passes around the tubes of the heat exchanger in order to remove or otherwise dissipate an amount of heat from the coolant as the coolant flows through the tubes of the heat exchanger.

[0003] A number of different types of heat exchangers have been developed for use with automobiles in order to reduce the temperature of a coolant utilized in the engine. One type of heat exchanger that has been developed specifically for use with an automobile engine is a heat exchanger having a generally circular cross section. Examples of heat exchangers of this type are shown in Goetz, Jr. U.S. Pat. Nos. 5,078,206 and 5,172,752 and Nakamura et al. U.S. Pat. No. 4,909,311, each of which are incorporated herein by reference.

[0004] In the Nakamura et al. '311 patent, a pair of generally circular headers or tanks are connected by a plurality of tubes that extend horizontally between the tanks. Sections of corrugated sheet metal are inserted and secured between adjacent pairs of tubes to provide increased surface area for the tubes to enhance the removal of heat from the coolant, e.g. water, flowing between the tanks through the tubes by the cooling fluid. To circulate the cooling fluid, the heat exchanger also includes a pair of fans disposed in the center of each header which draw the cooling fluid, i.e. air, into the heat exchanger past the corrugated sheet metal sections and around the tubes to thermally contact the heated water and remove an amount of heat from the water. The fans then discharge the heated air through the center section of each header at opposite ends of the heat exchanger.

[0005] A similar construction for a heat exchanger is found in the Goetz, Jr. '206 and '752 patents. In each of these patents, the heat exchanger includes a number of tubes connected between a pair of circular header tanks located at either end of each tube. The headers and tubes enclose a fan inside of the tubes between the headers. The tubes are each wedge-shaped and include a section of corrugated material, such as sheet metal, disposed between and contacting each pair of adjacent tubes. The heat exchanger operates in a manner similar to the Nakamura et al. '311 patent, with the fan drawing air past the tubes and corrugated material to remove heat from the coolant within the tubes before expelling the heated air through an open center section in each header. However, in these two patents, the tubes are wedge-shaped rather than circular in order to maximize the surface area available on each tube for heat transfer from the heated fluid flowing within the tubes to the air.

[0006] While each of the above patents discloses a heat exchanger capable of significantly reducing the temperature of coolant flowing through the tubes of the heat exchanger, the construction of each of the disclosed heat exchangers is difficult and time consuming to manufacture due to the number and complexity of connections that must be made between the respective parts of the heat exchanger. More specifically, each individual tube and corrugated section must be welded or otherwise connected to one another and to the respective headers in order to form each of the above heat exchangers. Each of these connections requires a significant amount of time and effort in order to insure that the connection is made properly in order to prevent leakage of the coolant from between the tubes and the headers, and to insure proper thermal contact between the corrugated sections and the tubes.

[0007] Therefore, it is desirable to develop a non-prismatic, e.g. cylindrical, heat exchanger which greatly simplifies the number and types of connections necessary between the tubes and the headers. Furthermore, the heat exchanger construction should allow for various configurations of the heat exchanger to be constructed such that the heat exchanger can be adapted for use with many different types of internal combination engines other than just automobile engines.

SUMMARY OF THE INVENTION

[0008] It is an object of the present invention to provide a non-prismatic heat exchanger which has a modular construction adaptable to conform to a variety of types of internal combustion engines with which the heat exchanger is used.

[0009] It is another object of the invention to provide a non-prismatic heat exchanger that has a modular construction that significantly reduces the overall cost of the heat exchanger and the amount of time necessary for assembling the heat exchanger.

[0010] It is a further object of the invention to provide a non-prismatic heat exchanger which utilizes a number of integrally formed heat exchanger modules in its construction.

[0011] The present invention is a non-prismatic heat exchanger including a pair of headers having an open center section that are spaced from one another and connected by a plurality of unitary heat exchanger modules that extend between the headers. Each header includes a hub disposed within the center section that supports one end of a rotating shaft of a rotor or fan located between the headers and enclosed by the heat exchanger modules. The shaft extends outwardly through the hub on one of the headers and is connected to a drive means capable of rotating the shaft and fan within the heat exchanger to force air between the heat exchanger modules. The air serves as a cooling fluid to remove heat from and reduce the temperature of a heated coolant flowing through the headers and heat exchanger modules. The arrangement of the heat exchanger modules and headers can be readily altered during construction such that the shape of the heat exchanger can be adapted for use with the particular engine.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The following drawing figures illustrate the best mode currently contemplated of carrying out the invention.

[0013] In the drawings:

[0014]FIG. 1 is an isometric view of a non-prismatic heat exchanger constructed according to the present invention;

[0015]FIG. 2 is a cross-sectional view taken on line 2-2 of FIG. 1;

[0016]FIG. 3 is a cross-sectional view taken on line 3-3 of FIG. 2;

[0017]FIG. 4 is an enlarged sectional detail taken on line 4-4 of FIG. 3;

[0018]FIG. 5 is a sectional detail taken on line 5-5 of FIG. 4;

[0019]FIG. 6 is an enlarged sectional detail taken on line 6-6 of FIG. 3;

[0020]FIG. 7 is an end view of a second embodiment of the heat exchanger of FIG. 1;

[0021]FIG. 8 is an end view of an alternate header construction for the heat exchanger of FIG. 1;

[0022]FIGS. 9a-c are end views of alternative modular heat exchanger tube constructions for use with the heat exchanger of FIG. 1;

[0023]FIG. 10 is a partial end view of the heat exchanger of FIG. 1 constructed utilizing the heat exchanger tubes of FIG. 9a;

[0024]FIG. 11 is an end view of the heat exchanger of FIG. 1 constructed utilizing the heat exchanger modules of FIG. 9c; and

[0025]FIG. 12 is a partial sectional view along line 12-12 of FIG. 10;

[0026]FIG. 13 is a partial cross-sectional view along line 13-13 of FIG. 12;

[0027]FIG. 14 is a partial cross-sectional view similar to FIG. 12 showing an offset configuration for the fins; and

[0028]FIG. 15 is a cross-sectional view along line 15-15 of FIG. 14.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0029] With reference now to the drawing figures in which like reference numerals designate like parts throughout the disclosure, a non-prismatic heat exchanger is indicated generally at 20 in FIG. 1. The heat exchanger 20 includes a pair of circular headers 22 disposed at either end of the heat exchanger 20. While the headers 22 are preferably circular in shape, the headers 22 can have any shape necessary for use with a particular engine type. The headers 22 are connected to one another by a plurality of heat exchanger modules 24 that extend between the respective headers 22.

[0030] Referring now to FIGS. 1-3, each of the headers 22 includes a central opening 26 defined by the header 22. To define the opening 26, the header 22 is formed of a circular inner wall 28 which is joined to a circular outer wall 30 by an outer end wall 32 and an interior side wall 34. The opening 26 is defined by the circumference of the inner wall 28 which includes a number of supports 36 that extend into the opening 26 from the inner wall 28. Each support 36 extends radially inwardly along a diameter line of the circular inner wall 28 and is used to fix a hub or collar 38 concentrically within the opening 26. Preferably the supports 36 are spaced about equidistant from one another around the circumference of the inner wall 28. The hub 38 is preferably formed as a generally cylindrical sleeve defining a central aperture 40 extending through the center of the hub 38.

[0031] Each header 22 also includes a fluid connector 42 secured to the end wall 32. When the heat exchanger 20 is in use, each fluid connector 42 is connected to a hose 44 which directs a fluid to be cooled either into or out of a header 22 through an orifice 46 disposed in the end wall 32 of the header 22.

[0032] As best shown in FIGS. 2 and 3, the interior side wall 34 of each header 22 serves as a header plate and includes a plurality of openings 48 which receive opposite ends of each module 24. The openings 48 enable the modules 24 to be placed in communication with the interior of each header 22 such that the fluid exiting or entering the header 22 can also flow through each of the modules 24.

[0033] Referring now to FIGS. 3-6, each of the modules 24 connected between the headers 22 is a unitarily formed, extruded tube formed similarly to that disclosed in Dierbeck U.S. Pat. Nos. 5,915,470; 5,383,517; and 5,323,707, which are herein incorporated by reference. The modules 24 can be formed of any generally rigid, thermally conductive material, with aluminum being the preferred material. Each module 24 includes a pair of opposed faces 50 and a pair of throughbores 52 which extend longitudinally through the entire module 24 between the faces 50. The number of throughbores 52 in each module 24 can vary depending upon the particular application for the heat exchanger 20, but preferably, as shown, two throughbores 52 are present in each module 24.

[0034] Each module 24 also includes a plurality of V-shaped grooves 54 extending along the opposite faces 50 of each tube 24. The grooves 54 on each face 50 extend parallel to the throughbores 52 and are bounded on opposite ends by a pair of flat end portions 56. The flat end portions 56 are sized to be able to be inserted through the openings 48 in the side walls 34. The end portions 56 for each module 24 can then be secured to the side walls 34 in order to form the exchanger 20 by suitable securing means. A preferred securing means for use in securing the end portions 56 to the side walls 34 are welds 58, as shown in FIG. 5.

[0035] Each module 24 also includes a number of slots 60 cut across each face 50 perpendicular to the grooves 54 and throughbores 52. The slots 60 do not intersect the throughbores 52 but serve to define a plurality of laterally extending saw-tooth fins 62 between each adjacent pair of slots 60. The slots 60 and fins 62 enable a cooling fluid, such as air, to flow through the slots 60 and past the fins 62 to thermally contact and remove heat which the module 24 has absorbed from a heated fluid flowing perpendicularly to the air within the throughbores 52.

[0036] The slots 60 extend along each face 50 between a pair of uncut sections 64. These sections 64 separate the slots 60 from the flat end portions 56 and serve to align the respective modules 24 with the headers 22 and with one another during construction of the heat exchanger 20.

[0037] The configuration of the openings 48 in each side wall 34 enables the modules 24 to be arranged in any pattern to enable the heat exchanger 20 to be shaped to accommodate the particular space in which the exchanger is to be positioned. As best shown in FIG. 3, in a preferred embodiment, the openings 48 in the side walls 34 of each header 22 are in a generally circular pattern around each side wall 34 such that the modules 24 are spaced in a staggered configuration around each side of the side walls 34. Further, as necessary, a pair of enlarged width modules 24 a are attached adjacent the top and bottom of each side wall 34 to provide a generally complete enclosure of the central opening 26 in each header 22. Alternatively, the enlarged modules 24 a could be replaced with a number of modules 24 positioned in line with one another. The staggered configuration of the modules 24 and 24 a enables a cooling fluid, such as air, to pass between adjacent modules 24 and 24 a through the slots 60 and between the fins 62 on each module 24 and 24 a. The direction of the flow of the cooling fluid is indicated by the arrows marked A in FIG. 3.

[0038] Referring now to FIGS. 9-15, three alternative embodiments for the modules 24 and 24 a are illustrated. In FIG. 9a, a module 24 includes V- or U-shaped grooves 66 on opposed faces 50 of the module 24 that extend parallel to a single throughbore 68 disposed within the module 24. The U-shaped grooves 66, conjunction with slots 69 that extend perpendicularly across the grooves 66, define fins 70 which can be positioned within the U-shaped grooves 66 on adjacent modules 24 to form the overlapping heat exchanger module configuration shown in FIG. 10. The fins 70 have a saw toothed configuration similar to the fins 62 of the previously described embodiments. However, the more U-shape of the grooves 66, results in somewhat smaller and narrower teeth 67 defining the fins 70. This configuration enables a heat exchanger 20 that is constructed in this manner to be smaller in size than the exchanger 20 shown in FIGS. 1-3 due to the nesting of the modules 24 within one another. Further, the effectiveness of the exchanger 20 is not reduced because a higher amount of turbulence is generated in the flow of the cooling fluid past the fins 70. This increase is graphically illustrated in FIGS. 12-15 where the overlap of the fins 70 on adjacent modules 24 and the flow path of the cooling fluid between the fins 70 is shown for both aligned (FIGS. 12 and 13) and staggered (FIGS. 14 and 15) arrangements of the fins 70. In the arrangement of FIGS. 12 and 13, the fins 70 on adjacent modules 24 are aligned horizontally, but the teeth 67 of one module enter grooves 66 in the adjacent module and are disposed between the corresponding teeth 67 defined by such grooves. In the arrangement of FIGS. 14 and 15, the fins 70 of one module are offset vertically with respect to the fins 70 of the adjacent module such that the fins 70 of one module are positioned between the similar fins 70 of the adjacent module. In this latter arrangement, the teeth 67 on adjacent modules may be either aligned or offset vertically. The increase turbulence increases the thermal contact of the cooling fluid with the module 24 and insures an amount of heat transfer between the heated fluid flowing within the throughbore 68 and the cooling fluid comparable to that achieved with the previous embodiment for the heat exchanger 20.

[0039] A similar configuration for the modules 24 is shown in FIG. 9b in which the U-shaped grooves 66 are cut deeper into the body of the module 24 in order to increase the surface area available for heat transfer and to reduce the amount of material the heat must be transferred through on each module 24. This further increases through the amount of heat that can be transferred from the heated fluid in the throughbore 68 to the coolant fluid flowing past the fins 70.

[0040] A fourth embodiment of the module 24 is shown in FIG. 9c. In this embodiment, the module 24 includes a number of V- or U-shaped grooves 66 formed on the opposite faces 50 of the module 24. The grooves 66 on opposite faces 50 of the module 24 are offset from one another such that the fins 70 on one face 50 are in alignment with the grooves 66 on the opposite face 50. This configuration enables the modules 24 to be positioned with the modules 24 in either a staggered arrangement similar to FIG. 10, or in an aligned arrangement as shown in FIG. 11. The arrangement of the modules 24 shown in either FIG. 10 or 11 positions the fins 70 of adjacent modules 24 such that all laminar flow of the cooling fluid past the fins 70 is disrupted and made highly turbulent to increase the thermal contact of the cooling fluid with the fins 70.

[0041] Referring again to FIGS. 1-3, the assembly of the headers 22 and modules 24 encloses a cylindrical fan 72 within the heat exchanger 20. The fan 72 includes a central shaft 74 that is rotatably mounted to each hub 38 disposed in the openings 26 in the headers 22. At one end, the shaft 74 extends through the hub 38 and is fixedly connected to a pulley 76. The pulley 76 is engaged by a belt 78 that is driven by a driving means in order to rotate the pulley 76 and the shaft 74. The driving means can be any suitable mechanism, such as a motor separate from the engine being cooled, but is preferably a part of the engine from which the coolant is flowing to the heat exchanger 20.

[0042] Within the heat exchanger 20, the shaft 74 is connected to a pair of generally circular rims 80 disposed adjacent each header 22. The rims 80 are held in position on the shaft 74 by a pair of bands 81 disposed on the shaft 74 against each rim and have a diameter slightly less than the diameter of the central openings 26 in each header 22. The rims 80 include a number of arc-shaped, open sections 82 in each rim 80. The sections 82 define a number of arms 84 extending outwardly from the center of each rim 80 in order to support a ring 86 forming the periphery of each rim 80. A number of rectangular vanes 88 are connected between the respective rings 86. The vanes 88 are circumferentially spaced from one another about the rings 86 and are each positioned along a radial line extending outwardly from the center of the shaft 74 through the vane 88. The vanes 88 serve to force the cooling fluid through the slots 60 and around the fins 62 of each of the respective modules 24 and 24 a as the fan 72 is rotated to thermally contact the cooling fluid with the heated coolant flowing within each of the modules 24 and 24 a. While the vanes 88 are preferably oriented as described above, the vanes 88 can be positioned at any angle with respect to the shaft 74 or in any other configuration needed to obtain the desired volume of air to be moved by the fan 72, such as in a helical or spiral configuration.

[0043] During operation, the heated coolant from the engine enters the heat exchanger 20 through a fluid connector 42 on one of the headers 22. The heated fluid is distributed by the header 22 into each of the modules 24 and 24 a such that the heated fluid flows through the throughbores 52 in each of the modules 24 and 24 a. At the same time, the belt 78 is driven by the driving means on the engine in order to rotate the pulley 76 and fixed shaft 74. Rotation of the shaft 74 also rotates the panels 80 and vanes 88 of the fan 72 within the interior of the heat exchanger 20. The rotation of the vanes 88 draws a cooling fluid, i.e., air, into the interior of the heat exchanger 20 through the central openings 26 in each header 22 as indicated by arrows A in FIGS. 1 and 2. The air drawn into the heat exchanger through the openings 26 is then forced out of the exchanger 20 by the rotating vanes 88. In exiting the heat exchanger 20, the air is forced between the modules 24 and 24 a through the slots 60 and around the fins 62 on each face 50 of the modules 24 and 24 a, as indicated by arrows B in FIGS. 1 and 2, such that the air contacts the slots 60 and fins 62. By contacting the slots 60 and fins 62, the air absorbs and removes an amount of heat present in the fins 62 which was thermally transmitted to the fins 62 from the heated coolant through the body of the module 24. The air thermally contacts the heated fluid along the entire length of the module 24 until the heated fluid reaches the opposite header 22. Upon reaching the opposite header 22, the now-cooled coolant exits the modules 24 and is directed by opposite header 22 into a fluid connector 42 for recirculation through the hose 44 and back to the internal combustion engine to provide additional cooling for the engine.

[0044] While the above description illustrates the best mode currently contemplated of practicing the invention, other alternative embodiments of the invention are also contemplated. For instance, with reference to FIG. 7, each header 22 can be formed as a semi-circular hollow body 90. The hollow body 90 is formed similarly to the header 22, including openings 48 for the insertion of the modules 24 to connect a pair of hollow bodies 90 at opposite ends of the modules 24. Each hollow body 90 is also connected at each end to a semi-cylindrical cover plate 92 at opposite ends of the plate 92. The fan 72 is attached between the holes 38 on each hollow body 90 and is enclosed by the hollow bodies 90, the modules 24 and the cover plate 92. The cover plate 92 extends continuously between the respective hollow bodies 90 and serves to direct all of the air drawn through the central openings 26 by the fan 72, between the modules 24 extending between the hollow bodies 90 to obtain enhanced heat reduction in the heated fluid flowing through the modules 24.

[0045] Furthermore, as best shown in FIG. 8, each of the headers 22 can be formed of a pair of hollow bodies 90 of FIG. 7 joined in fluid communication and connected directly to one another at opposite ends, as by welding.

[0046] Various alternatives are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention. 

I claim:
 1. A non-prismatic heat exchanger comprising: a pair of headers disposed on opposite sides of the heat exchanger, each header including a body having a curved shape, an inlet on one side of the body, at least one outlet spaced from the inlet, each body defining a center opening; a plurality of unitary heat exchange modules interconnecting and providing fluid communication between the headers and surrounding the opening in each header to define a hollow interior within the heat exchanger, each module including at least one longitudinal throughbore extending the length of the module and in fluid communication with the headers at each end, and a plurality of slots defining heat transfer fins extending across the module perpendicular to the one throughbore; and a rotor disposed within the hollow interior of the heat exchanger, the fan including a central shaft rotatably mounted to the headers at each end and a plurality of vanes connected to the shaft.
 2. The heat exchanger of claim 1 wherein the headers are generally semicircular in shape.
 3. The heat exchanger of claim 2 further comprising a panel secured to opposite ends of each header to enclose the opening in the headers.
 4. The heat exchanger of claim 3 wherein the panel is generally semicylindrical in shape.
 5. The heat exchanger of claim 1 wherein the headers are generally circular in shape.
 6. The heat exchanger of claim 5 further comprising a collar disposed within the opening of each header and connected to the header by a number of supports, wherein the central shaft of the rotor is rotatably mounted to the collar.
 7. The heat exchanger of claim 6 wherein the collar and the number of supports are integrally formed with the headers.
 8. The heat exchanger of claim 1 wherein the slots are cut into opposite faces of each module to define the fins.
 9. The heat exchanger of claim 1, wherein the modules are provided with a plurality of grooves extending along each face of the module parallel to the throughbores, such that the slots define the toothed fins.
 10. The heat exchanger of claim 9 wherein the grooves are generally V-shaped.
 11. The heat exchanger of claim 9 wherein adjacent modules include fins that are offset from one another such that fins on one of the adjacent modules are insertable into the slots on the other of the adjacent modules.
 12. The heat exchanger of claim 2 wherein the headers each include a pair of semi-circular hollow bodies that are connected by a pair of header extensions at each end.
 13. The heat exchanger of claim 5 wherein the header is formed of a pair of semi-circular headers secured to one another at opposite ends.
 14. The heat exchanger of claim 1 wherein the vanes are disposed on the fan along radial lines extending from the shaft.
 15. The heat exchanger of claim 1 wherein the vanes are disposed on the fan in a helical configuration. 